Obama set to announce a major US draw-down in Afghanistan.

US President Barack Obama delivers his State of the Union address before a joint session of Congress on Capitol Hill on January 24, 2012 in Washington, DC.The president called economic inequality "the defining issue of our time." (Saul Loeb-Pool/Getty Images)

White House sources on Tuesday said US President Barack Obama will announce the withdrawal of 34,0000 US troops from Afghanistan within the year, slashing the force by nearly half, according to reports.

The announcement is expected during Obama's state of the union speech, which is set for late Tuesday.

It comes as Pentagon officials on Tuesday protested looming budget cuts, with Deputy Defense Secretary Ashton Carter telling Congress that hundreds of thousands of jobs will disappear if the agency endures a threatened $46 billion cut, according to Reuters.

Like other federal agencies, defense is operating on short-term funding that expires on March 1, prompting Carter to warn that quick cuts could "create an immediate crisis in military readiness," Reuters reported.

Funding issues are also likely to affect US troops abroad, including Afghanistan, where some 66,000 US troops are currently posted. White House officials said Obama isn't likely to touch on keeping any forces there after 2014, the deadline for international forces to withdraw. Earlier reports suggested the administration had considered an arrangement that would leave some 9,000 troops there beyond the deadline in order to help with security,the BBC reported.

Also citing officials, USA Today said Obama's draw-down announcement isn't expected to change earlier agreements the final end of combat operations there.

Here's CNN's Jake Tapper with more on Obama's anticipated announcement: